Improvement in treating waste rubber



F -NITEI) STATES PATENT OFFICE..

e; H. i HAYWARD, OF STONEHAM, AND DANIELE. HAY-WARD, on MELROSE,

' MASSACHUSETTS;

- IMPROVEMENT IIN' TREATING-WASTE RUBBER.

,Specification forming part of Letters Patent No.40,407, dated October'27, 1863'.

To all who m it may concemt: I

'Be it known that we, CHARLES H, HAY- WARD, of Stoneham,.in thecounty'ol' Middlesex and State of Massachusetts, and DANIEL E. HAYWARD, of Melrose, in the county and ploy the waste rags of 'india-rub-ber manufac-- tories, which con'sistot' scraps of' cotton and other cloth covered with unvnlcanized'rubber, by grinding them 'upon the ordinary heated rolls and mixing themwith fresh or crude rubber; butt'he tenacity of the fibers made it exceedin gly difficult to grind the material to a uniform consistence, and their presence inva'-.

riably caused the gum to blister during the. process of vulcanization, so that it has not been found: practicable to employ them in themanufaetu're of any but the cheapest and coarsest articles-as, for example, the packing I avetherefore give the-preference toth'esuh .phuricacid as the most economical, efl'ectual,

for steam-engines.

-Our-:invention,.which has for its'object to remedy the above objections vto the employment of these articles, consists in" destroying the tenacityof the fibers previous togrinding the rags by boiling the wasterags in an acid.

or alkali to destroy the cotton or o'ther'fiber,

- so that they'may be easily and speedily ground uponthe hot rolls, and so that the material will not blisterwhen'run-upori cloth and sub sequently vulcanized.

That others skilled in the art may understand our inventiomjwe'will proceed-to de scribe the method by which-we have carried it, out-in practice.

One thousand pounds'of the rags-or other fibrous india-rubber articles are boiled fora space of ten to twelve hoursin a mixture of eighthogsheads of water and seventy --five pounds sulphuric acid, the boilingbeing .ef-- fected by means'ofcoppersteam-pipes arranged v 'in the bottom of a wooden tank; The acidis now removed by thorough washing,-and this .part of the process we prefer to efl'ectbysub' mittin-g .the rags for the space. of three to- 'six hoursto the action of steam'under a pressure of seventy-five to one hundred and twentyfive pounds. After being dried the rags are ground upon the heated rolls, the tenacity of the fibrous, portion beingso effectually 'destroyed as to crumble to powder in a short space of-- time and becomethoroughly incor porated with the rubber. Twelve .pounds'ofthe vground rags are then ground [with three pounds of fresh or cru'de rubber, mixed with g I suitable proportions of mineral orother ingredients, and the compound thus produced may be employed in the manufacture of various articles, and may be vulcanized without blisteringor swelling; T

There are other materials which may be em:v

ployed for the purpose ofdestroying the tenao. ity of the fibers besides the one above indicated -as, for example, caustic alkaiies but these-require a greater length of time, unless they are made very strong, in whiehcase they i become tooex'pensive foruse in practice, and

and expeditious.

- In lieu ofgrinding the fibrous portions of} the-rags, and the indiarubberf together, as!- above indicatedfthe two maybe'easily'sep'a to be used alone, if desired.

.- What we claim asflour invention, anddesire .to secure by Letters Patent, 1

'Boiling'waste' rags' of 'fibrous material and rubber in an acid or alkali for the-purpose of destroying the tenacity. of the fibers ofa'the .rag's, so that the rubbermaybe reground,'-a-nd ,so that the material will-not blister" when re used,-'as described.

H. HAYWARD;

1). 'n. HAYWARD;

Witnesses: v Wm-H. HILL, G ORGE T. BAILEY.' 

